I don't think that you can run a VBScript from within an FDM report, reports as I understand them are relational queries into the underlying FDM tables.

However, what you can do is create a VBScript that executes a report so look at whether you can add an event / custom script that executes the report you are looking for. It is also possible to set up email capability so you may be able to generate and send the report as part of a single script.